Power brake



Sept. 20, 1932.

N. LOMBARD P OWER BRAK E Original Filed Feb. 9, 1929 2 Sheets-Sheet mrwfNNW

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N. LoMBARD sept. 2o, 1932.

POWER BRAK E orig-inalFiled Feb. 9. 1929 2 Sheets-Sheet Patented- Sept.20, 1932 PATENT orf-lcs NATHANIEL LOMBAVRD, F WORCESTER, MASSACHUSETTSPOWER BRAKE i,

Application filed February 9, 1929, Serial No. `33858515. vRenewedSeptember 24;, 1981. i

The objects of this invention arev to provide, in a. cheap, reliable andpractical man. ner, manual and power means for setting the.

brakes on V.a moving car, a resistance to the movement of the footleverwhich is much less than,but proportional t9, the application of-power to the brake rod and means forevercoming the tendency of power-oerated brakes'to give sudden and startling raking lo effects with butslight movements of the brake lever.

`Reference is to be had to the accompanying drawings in which Fig. 1 isa side view showing how the brake is connected up; n a

Fig. 2 is a diametrical sectional view of a -preferred embodiment of theinvention, showing it in normal inactive position;

Fig. 3 is an end view;

act of applying the brake initially, and

Fig. 5 isa similar view, showing the extreme position of the parts.rl`his brake-applying power means consists, essentially, of a flexiblediaphragm covering one side of a casing, thespace between beingconnected at will to the intake manifold of a revolving internalcombustion engine orto the air. The diaphragm actuates a flangemountedon one end of a valve sleeve, which sleeve `itsand slides in the hub ofthe diaphragms casing and is operatively connected with a compound linkwhich fits and slides in the said valve sleeve and constitutes a part3.-, ofthe mechanical connectionbetween a foot pedal or other brakeapplying means and n brake rigging. v

The compound link has three parts. Part one is a. round rod 8 having aneye for a pin io connection at its left-hand or pedal end, a port 18bored axially from its i right-hand or brake end and extending nearlythrough it, and two lateralcross Cuts, or ports, 13 and 14, through itsside. Part 'two is a round rod 'i 9, having an eye piece 6 screwed onits righthand end and-constituting also one of a pair 3 and 26 ofgrippin anges for securing the iexible diaphragm by its centerto saidrod, `the rod having a hole 19 bored axially into 5o it from its pedalend to said flanges and hav- Fig. 4 `is a view like Fig. 1, but in theations in said flange permitair to flow freely ing a lateral port cutinto it at flange" 3. This right-hand link-rod 9l is extended to the`lef-t and turned to enter, lit and slide in a short recess in the brakeend of link-rod 8, t-hereby forming a continuous port through the linkand also ksteadying that end 'of the rod. Part three is a stiff coiledsteel spring 5 which unites the -two rods' 8 and 9 by attachmenttheretoand is normally neither extended nor compressed. The referable 60method of attachment ofthe sprln "to the rods is to screw the springtight y on a' threaded-portion of eachv rod, the thread sections beingshaped to fit thecoils. vThe rod 8 has its threaded portion on itsright-hand 65 end while the rod l9 has its threaded portion j near themiddleof its length. The arrangement leaves several coils between thesetwol` threaded portions unengagedby either thread and capable ofaction'as a tension'sprin 70 This compound link fits into and sli es ina long sleeve 16 extending from a point 'close to the ange 3`to 'a-point close to the lefthand end of the link 8, and carrying on thevformer end a flange 1. This sleeve 16 itself 75 fits into and slides ina shorter sleeve 10 fixed in position by firm attachment to the carbody. The shorter sleeve* 10 carries integral with itat. its-brake end adiaphragm casing.

2, to the outer rim of which is secured the 80 corresponding moulded rimof alexible diaphragm 7, the center of the diaphragm being pierced by ahole, the edge of which is` pref` erably thickened so as to be readilygripped between the aforesaid ianges 3 and 26.

The brake end of the long sleeve 16 is threaded into a boss 24 centrallylocated on a perforated diaphragm flange l1. The perforbetweenits twosides.' The' centralv part of this-flange has a hole .large enough forthel link member 9 to slide through and the annular part ofthe angesurrounding the hole .acts as an abutment for a ferrule 23'carried 95 von the link member 9, and which is pressed upon by a powerful helicalspring 4. This spring surrounds the hollow part ofthe llink member 9.andexerts pressure on the brake i end of the tension spring member 5 `ofthe 'Irf link. The compound link having been fas-,

compound link. The link-rod 9 fits and slides freely in the ferrule 23.

The left-hand end of the long sleeve 16 carries, firmly attached to it,a 'smallcasing 11 which has a two-fold object. It provides a place for akey bolt 21, by means of which the brakes may be set by the mere pull ofthe pedal onthe compound link in the usual way, should the car be movingwhile the engine is not rotating and hence not producing suction. Inorder that the engine vacuum may be connected or disconnected with theinside of the compound link, play enough is allowed in the fit of thekey bolt in the left-hand link-rod 8 to permit suflicient motion of thesaid rod 8 relative" to the position of the sleeve 16 to allow-ofconnecting the ports 13 and 12 or ports14 and 15; and the casing 11 alsoserves as the terminal chamber of a flexible y.

tube 17Y connecting the inside ofthe link with the intake manifold ofthe engine through a lateral port 12, cut through the casing-envel- 4oped end of the sleeve 16 and situated slightly to the left of .the linkport 13.

TheV key bolt is put there merely to make sure of the connection betweenthe footand the brakes in the case of absence/of vacuum; but the springkis really and practically suffieient, although, of course, not soabsolutely certain not to break. lThe bolt is insurance which costsnothing since such a bolt must be usedto pinch the casing k11 so as tovhold it by friction firmly in place on the end of the casln r. v Y Ii-,lo attach the device toa car, `a section of the pedal brake rod iscut out and eye-bolt stud-ends are screwed to thetwo cut ends', thedistance apart of `their pin centers when the pedal is raised beingLequal to that between the eyes at each end of the unextended compoundtened by ins to the said stub ends, the casing 2 is astened to the bar,lbody in such .a position that its axis is on the original axis ofthebrake rod and its flexible diaphragm 7 is fully extended to the left, asshown in Fig. 1, butnotjso fully as to interfere with the necessarydegree of slack in the brake rigging required to permit free running ofthe car, which slack is maintained by the` brake retractile springsalways provided in brakes for that purpose.

The spring 5 is located in the space between the sleeve16 and thetwomembers 8 and 9 of the brake rod link.v `The interstices of this spacepreferably are filled with lubricating grease, Vwhichv may pass througha vent port 30 into the Vcomparatively loose bearing 10.

TheA operation of the power means when connected by flexible tubing tothe engine intake will b e as follows: Starting with the parts in theposition shown in Figs. 1 and 2, the rst slight depression of the pedalmoves the entire compound link tothe left, without change in its overalllength, until the resistparts its immobilitv tension spring 5 forpression ofthe pedal.

g 7 and its casing 2 to lower its pressure by expansion out of thecasing and into the engine throughy irregularities in the surface of theflange 3, the port 2O in the right-hand linkmember 9, the long centralholes 19 and 18, the ports 13 and 12 andthe flexible tube 17. Theexternal atmospheric pressure on the diaphragm 7 then forces thediaphragm flange 1 vtowards the pedal, compressing the right-A handspring t-andputting thereby a pull on the brake rigging additional tothat of the foot. yAt the same time, provided the brake. lever istheniheld stationary, the long sleeve' 16, to the right-hand end ofwhich the diaphragm flange 1 is attached, is moved to the v left untilbymoving the port 12 past the port 13, it again cuts ofi' the portconnection be-l tween the engine suction and the inside of the link rodsand thus, by preventing further expansion of the yair'contai'ned in thespace between the diaphragmand its casing` prevents temporarily anyincrease in braking effect. The pull on the brake rigging is alsoincreased by the unbalancedair pressure actingdirectly on the flange 26.When the brake rigging has had its slack-motion taken 'out of it by theinitial depressions of the pedal, it is held stapedal motion andimtionary against mor the brake end of the shown in Fig. 4. I

' As soon, therefore, as the two ports 12 and 13 are reconnected byadditional pedal depression, such pedal depression must beaccom-` paniedby an extension and increased resistance of the spring 5. as well, as bythe resulting increased pressure of the outside air'on thel diaphragmwith Y its accompanying int/liespring 5 is attached `to theright-hand-link rod 9 which is itself l a part ofthe brake rigging. Thisposition is creased braking effect. The extreme position which may bereached and which puts the heaviest pressure both on the brake and on'the foot, isshownin Fig. 5.

It is thus apparentl that the tension on the and-varying as it does itsreaction on his foot proportionally to the variation in the-total forcesactingon the brake rigging, affords him a realizing indication of theamount of tension-spring v5, controlled by the operator braking forcebeing exerted by any given de- The outstanding peculiarity of thisinvention is, however, more -had its Vslackmot-ion absorbed and comesubstantially to rest. The especial advantage I of thisresult of thecombination is that the brakes may be applied gently and smoothly withfar less skill and fatigue on the part of the operator than is the casein those power means wherein the foot abruptly stops moving if the brakerigging stops moving and foot pressure alone, without much of any footmovement, has to be relied upon to produce any further brakingefects.

The brakes are released in the usual way, the removal of the footpressure allowing the rods for operating the brakes and the usualsprings forming partof the brakes to move the rod 9 of the compoundlink-rod to` the right. This Amotion acts through the spring 5 to movethe rod Sito the right, thereby aligning the port 14 with the air port15 in the position shown in Fig. l. The air port 15 is. cut through thesleeve 16 to the outer air and is situated between the small casing 11and the end ofthe diaphragm casing sleeve 10. It permits the outer airto reenter the interior of the casing 9 and thus balance the atmosphericpressure onl the diaphragm 7 .Y Thecompression spring 4 is preferablywound with` suiiiciently open coils to permit the diaphragm flange tomove nearly up to the casing under the conditions of the relativemotions of the two Ysleeves 16 and 10 before the coils are compressedagainst each other; and the spring, when so compressed, should besulliciently powerful to fully operate the brakes, aided, as itis, bythe extension of the left-hand spring bythe foot. It should be observedthat the total possible motion of the diaphragm flange 1 towards itscasing is muchV greater than ythe -surn of the spaces between thecompression spring coils, since `the left abutment of this spring itselfhas motion to the left. Ifvthe vacuum in the engine is non-existentk thebrakes may be manually operated with pracjtically'no resistance from thepower means.

Although I have illustrated and described only one form of theinvention, I am aware ofthe fact that modifications can be made thereinby any person skilled in the art without departing from the scope of theinvention as expressed in the claims. Therefore,

I do not wish to be limited in `this respect, but what I'do claimY is 1.In a brake applying device, the combination of a casing and a flexiblediaphragm connected therewith and forming an enclosed space `with oneside thereof, of means for connecting' said space'a't will with an'internal 4,combustion engine intake .mani'fold, a valve sleeve'4 havmgaange inl-position lmeans. for transmitting. the motion.

fits and slides, and a compound linkfittingV andsliding in saidsleeve,operatively conn'ected thereto, and constituting an extensiblemechanical connection.

2.1m a brake a plying device, the combination Vwith abra e riggingand anoperating lever,l of a yieldin ly-extensiblev compound link connecting tem, means whereby the iirst slight movement of the lever in a directionto applythe brake moves the compound link without extending it until theresistance offered-,bythe brake rigging stops it, means whereby furthermotionof the lever in the same direction extends'the link and puts'apull on the brake rigging and also moves'theend thereofnearest thelever, said end-'of the link having aport, which by said motion openscommunication to a source ofreduced pressure and av flexible diaphragmhaving a space on one side, said link having a passage from the port tosaid space, whereby the external air on ythe other side of the diaphragmwill move it and of the diaphragm to the brake rigging.

, 3; In ya brake operating device, the combination with an operatingpedal and vbrake rigging,- of a compound link connecting them, said linkcomprising two members in alignment having a continuous longitudinalpassage therein and relatively movable and an extensiblespring tendingto hold them together,`a flexible diaphragm open to the air on'one sideand connected with the passage through said compound link on the other,v

' member ofthe link having a porttadanted to be connectednwith a sourceof reduced-lair Y' pressure when the pedal is depressed. .Y

4. In a brake operating device,- the combination withv anoperatin pedalland brake rigging, of a compound lin connecting them,

said link comprising two members having a continuous longitudinalpassage therein and relatively movable 'and an extensible spring`tending to hold them together, asleeve in Vwhich the threel parts of thecompound link are contained, a flexible diaphragm open to the air on oneside and connected withl the passage through said compound link on theother, and meanswhereby the force of the diaphragm when the air ispartly exhausted from one side of it will be applied to said I sleeve tomove it bodily, the sleeve and one member of the link having portsconnected 'with the source of reduced air pressure andl adapted tocomeinto registration when the pedal is depressed. -j Y f `lily-In a'brake operating. device, the comzo *f j 6. In fa brake operating.device, the-com .reduced `air pressure andY afventing port,yieldingmeans for resistin the `separation of the two parts of the lin,1a dia hragm Vhaving its center connected positive y with the brakeriggin and its outer rim in fixed l' position, one -si eof the diaphragmbeing with said interior passage, and means adapt-` open to the airy anda fixed chamber on `the other side, portsv for connecting the chamberedtobe engaged by the diaphra m for push` ing one member of the componnklink toward the Vpedal when ythis chamber iis connected with the sourceof reduced air pressure;

bination with` a foot pedal and a brake rig- ',.gingof a compound linkconnectinglthem, said link comprising two relatively movable members andhaving a longitudinal air pas-- sage through them, and an extensiblespring secured to y'said two members and normally tending to hold them.together but capable gielding, a sleeve in which the compound 3 lin islocated,a diaphragm,-one side of which is open to vtheair and a fixedchamber on the other side, vone ofthe members ofthe compound link havingports for connecting the chamber with thesource ofreduced air 1n adirection to reduce the` contents of said chamber and means adapted tobe engaged by the diaphragm for pushing the sleeve and one member of thecompound link toward with thejsource of1 reduced air pressure.

7 In la brake operating device,'the combination of-.a'movable sleeve, a.flexible connection from the intake manifold ofanV internal combustionengine fixed to said sleeve, saidsleeve having a port communicating withthe fiexible connection, a compound link connectedwith the sleevecomprising two members, onev having a port adapted to communicate withthe first named port according to the positionof the-parts, the othertelescoping therewith and having a port beyond the end of the sleeve, acontractible vspring connecting the two parts together and normallytending to urge them into close contact, a diaphragm connected with thesecond mentioned member of the compound link, a diaphragm fiangeconnected with the sleeve against which, the diaphragm can move with acertain pressure toward the sleeve, whereby when the first two mentionedports are in registration the air will be exhausted from Y* one side ofthe diaphragm and the sleeve and `one member of the compound link willbe u forced toward the pedal.

ber of the link having aport which will conneet the interior .passagewith a source oi l ressure, whereby the diaphragm will move the pedalwhen this -chamberis connectedv 8. Ina brake operating device, the combinationv of a stationary bracket having a cylindricalpassagetherethrough, a sleeve movable in said passage, a flexibleconnec- 'tion from ythe intake manifold of a combustion engine fixed tosaid sleeve, said sleeve having a port communicating-"with:the flexibleconnection, two link members, one having a port adapted to communicatewith the first named port according to the --position ,of

the parts, the other havinga port, ra;con

tractible spring connecting the two parts together, a compression springconnected with said sleeve for transmitting pressure to one member ofthe link, the latter spring beingy sof-wound that `the .coils do `notcome together-to constitute a. stop, until the end of its. travel, `adiaphragm connected with the second link member, a diaphragm Harige.

connected withthe sleeveagainst which the diaphragm can move-wherebywhen the first two mentioned portsfarein registration the air will beexhausted from `one side of the diaphragm and thefslecve and one memberof the compound link will be forced toward thepedal.. t, t

'9. In a brake operating device, thecombination with a foot pedal, abrake rigging and, a compound flexible link connecting them, of4

a sleeve movablymounted with respect to the link, a diaphragm casingvprovided with .a cylindrical fiange, a fiexible -diaphragm providedwith a cylindrical portion secured to vsaid flange, an eye pieceslidably connected with said link and having a pair of flangesy betweenwhich the open center ofthe diaphragm is secured and a diaphragm flangemounted on the end of said link and in positi onto engage the di hragmbeyond the circumference ofthe t o flanges on the eye piece -for thepurpose described.v

l0. In a brake operating device, the combination with an operating pedaland brake rigging, of a compound .link connecting them, said linkcomprising two members in alignment havinga continuous longitudinalpassage `therein and relatively movable and an extensible spring tendingto hold themtogether, a flexible diaphragm open tothe air on one sideand connected with the passage through said compound link on the other,means controlled bythe pedal for connecting the passage in said compoundlink'with a source of reduced air pressure and means whereby the forceof the diaphragm when the air is partlyv exhausted from one side of itwill move one member of the compound link toward the pedal. i

In testimony whereof I have hereunto' affixed my signature.

NATHANIEL LOMBARD.

